1. Field of the Invention
The present invention relates to toilet flush valves and, more particularly, to a double flush toilet valve and the method for providing a double flush conversion for a standard toilet. The valve of the present invention is very similar to a standard toilet flush valve except that it has an additional vent hole in the float portion thereof which can be opened when the float valve has been actuated to flush the toilet. This is done by providing an extended additional force pull on the toilet handle to open the vent hole whereby water enters the float portion of the valve and partially floods it causing it to have negative buoyancy and eventually to sink prematurely as compared to a standard valve. However, the partially flooded float valve is prevented from sinking and closing the discharge outlet of the toilet water tank until a partial flush has occurred.
2. Description of the Prior Art
The present invention is a modification to a standard toilet float valve which permits the valve to accomplish a double flush. The standard float valve most commonly used today is a rubber flapper valve which is actuated by a pull chain. When the toilet actuation handle is tripped, the chain lifts the float out of its sealing relation on its seat in the discharge outlet of the toilet tank. The float, due to its buoyancy, remains suspended in the water in the toilet tank until the water level recedes, due to the outrushing water, low enough to allow the float to reseat in the discharge outlet and the water tank to begin to refill.
There have been numerous designs which have modified a standard toilet flush valve to allow a shortened flush, such as U.S. Pat. No. 3,969,775 to Haselton issued Jul. 20, 1976, for a Water Closet Flushing Device. This device uses a separate float for the valve attached to the trip chain which is one of the features utilized by the present invention. However, Haselton does not permit a full volume flush; just a shortened one.
U.S. Pat. No. 4,000,526 to Biela et al., issued Jan. 4, 1977, for a Toilet Flushing Apparatus, permits either a partial or complete flush of a toilet which is the same purpose as the present invention but the design of Biela et al. requires a more complicated and different mechanism than the present invention.
U.S. Pat. No. 4,160,294 to Crumby issued Jul. 10, 1979, for a Two-Stage Flush Mechanism For Toilets, accomplishes the same result as does the present invention, and by a similar actuation means, but it requires a completely different and more expensive mechanism to do so.
The modification of the present invention to a standard toilet float valve, which permits a partial as well as a full flush, is provided by attaching a supplemental float to the flush valve and providing an opening in the lower end of the valve float which permits it to intake water and acquire negative buoyancy before the full discharge of the water tank has occurred. As a result, the valve float tends to sink in the outgoing water when its buoyancy becomes negative, but it is prevented from sinking completely and closing the discharge outlet until at least a portion of the tank is emptied by virtue of the separate additional float attached to the valve.
The referenced prior art does not teach the simplified apparatus of the present invention for providing selective partial or full flushing of a toilet by a standard toilet and its actuation mechanism.